Ammeter



(No Model.)

W. HOCHE'AUSEN.

,. AMMETER.

Patented July 11, 1893.v

Figi.

1N VEN TDH:

NITED STATES PATENT OFFICE.

WILLIAM HOOHHAUSEN, OF BROOKLYN, NEW YORK.

AMMETER.

SPECIFICATION forming part of Letters Patent No. 501,144, dated July 11, 1893.

Application filed February 28, 1891. Serial No. 383,157. (No model.)

.To @ZZ whom t may concern.-

Be it known that l, WILLIAM HocHHAUsEN, a citizen ofthe United States, and a resident of Brooklyn, in the county of Kings and State of New York, have invented a certain new and useful Ammeter, of Which'the following is a specification.

My invention relates to the construction of ammeters, voltmeters and similar devices for indicating the strength or potential of electric currents.

One of the objects of my invention is to provide means for indicating not only the strength of current or potential, but also for showing by the same instrument the polarity of the electric current.

The invention is especially useful for ammeters used on circuits supplying electric arc lamps in series in which case it sometimes happens that the polarity of the machine may become reversed and current flow in reverse direction over the circuit without the knowledge of the attendant at the central station. The result is, frequently, that serious damage is done to the electric lamps or other apparatus by reason of the fact that the current passes through the same in the reversedirection to that intended for the lamp.

My invention consists essentially in the combination with an ammeter, of a polarized visual indicator or tell-tale placed in the field of the ammeter magnet.

My invention consists further in certain details of construction of the ammeter or potential indicator, the objects of which are to pro duce an ammeter that shall be simple, cheap and durable.

In the accompanying drawings:-Figure l, is a plan of an apparatus embodying 'my in- Vention. Fig. 2, is a side elevation and partial vertical section of the same. Fig. 3, is a plan of one of the conducting plates or blocks to which connection with the circuit wire is made. Fig. 4, is a side elevation of such block detached from the insulating base.

A, indicates an insulating base of slate or other suitable non-fusible or combustible insulating material and C, is the casing fastened to said plate and surrounding the parts of the apparatus also fastened or secured upon said base plate.

B, indicates the ammeter electro-magnet the coils of which are wound upon a spool B2, of brass or other metal which is cast in one piece with arms or brackets D, D2, which serve to fasten the magnet to the base plate A. Screws passing from the back of the plate A,into said brackets or arms are used for the purpose of holding them down upon the plate. The bracket D, also forms a terminal by which electric connectionmay be made with a circuit wire, for which purpose it is provided with a post or extension D3, preferably cast in one piece with it and extending down into an opening in the base A, in line with a passage or opening extending linward from the edge of the plate whereby F, which moves over a scale upon a scale plate G. The scale plate G, is fastened to the posts, as indicated, which project from the base plate A, and are secured by screws passed through the back 0f the plate. The scale plate carries a suitable stop pin for the pointer F, as indicated.

Hung from the rock shaft E, is a pin or bar H, of soft iron which is fastened to an arm H2, consisting of a thin piece of metal, such as brass, secured tothe rock shaft, as indicated more clearly in Fig. 2. The pin or bar H, passes, preferably, t-hrou gh the hollow center of the spool and is parallel to another bar or pin H2, which also extends through the spool and is carried by a bracket H4, of brass or other suitable material fastened upon the outer end of the spool, as clearly shown. The two bars or rods H, H2, being of similar polarity, the bar or rod H, will obviously be repelled away from H2, with the effect of causing the pointer to move over the scale in obvious manner to a point corresponding to the strength of the exciting current flowing in the coils of the electro-magnet.

One end of the coils of the electro-magnet is connected directly to the spool of conduct-V ing material which, as explained, is in connection with the post D3. The other end of the coil connects to a plate or block I, of conducting material and is fastened down thereupon by a suitable binding screw. The plate or block I, is secured to the face of the base A, as clearly shown,and is also provided with a binding post I2, cast in one piece with it and arranged in line with an opening extending inward from the edge of the plate A, whereby the other terminahwire of the circuit may be connected to the apparatus.

I3, is the binding screw that serves to hold the wire in the socket in the post i2.

The visual indicator or tell-tale which serves to show the direction of current on the circuit, may be constructed as followsz M, is a needle, bar or rod of steel which is permanently magnetized or polarized and is mounted upon asuitable pivot M2, upon which it may turn freely to set itself with one end or the other turned toward the face of the instrument, according to the direction of the current flowing through the coils B. The needle or bar M2, carries at its ends suitable disks or plates O, O2, which should be of sufficient size to be clearly visible and which are preferably colored, that one which is exposed to view when the current on the circuit shall become accidentally reversed being preferably colored red while that which is turned toward the face of the instrument so as to be exposed to View when the current is normal in direcl tion is white. A mere glance at the instrument will show, therefore, not only the amount of current flowing, but whether the current is fiowing in the normal or proper direction or not. The pivot M2, may be supported upon a bracket P, fastened to the underside of the scale plate G, as clearly shown.

R, is an arm extending from the plate or block D, and serving to hold the indicator down upon its pivot and to prevent displacement during transportation.

Aswill be obvious the bar or needle M, be-

ing within the magnetic field of the electroi magnet which operates the ammeter arm F, will respond to any reversal of the current in the ammeter coilwith the edect already stated.

I do not limit myself to any particular form or manner of mounting the polarized element of the device which is exposed to the infinence of the ammeter magnet and show the particular form herein illustrated only as a means of exemplifying the invention.

What I claim as my invention is- 1. The combination with an ammeter or voltmeter, of a polarized visual indicator o'r tell-tale placed within the field of the ammeter magnet, and provided with means for showing to the eye a reversal of currentin the ammeter.

2. The combination substantially as described, with an ammeter or voltmeter having means for indicating the strength or potential of the current, of apolarized pivoted bar or needle placed within the field of the ammeter magnet, and provided with a tell-tale indicator or disk exposed to view when the normal direction of current in the ammeter magnet is reversed.

3. In an ammeter or voltmeter, an electromagnet the spool of which is composed of a 'casting of conducting material cast in one piece with an arm or bracket having means for attachment of a wire of lthe circuit, as and for the purpose described.

4. In an ammeter or voltmeter, the combination with the hollow spool, of a rock shaft mounted therein, a rod or bar of iron hung from said shaft and extending through the spool parallel with its axis, and a second rod or bar of iron extending through the spool parallel with the first and fastened to a head of said spool.

5. In an ammeter or voltmeter, an electromagnet, the spool carrying coil of which is composed of a casting of brass or other suitable conducting material having two arms or brackets cast in one piece with it, a base plate casting of conducting material and is included in the electric circuit of the magnet coils, as vand for the purpose described.

7. In an ammeter the combination substantially as described, of the hollow coil spool having suitable brackets or arms fastened to the base plate, a rock shaft parallel with the axis of the spool and mounted in bearings secured to opposite heads of said spool, a bar of magnetic material suspended on arms projecting from said rock shaft and extending through the hollow spool parallel with its axis, a second bar or piece of magnetic material parallel with the first and suitably ixed inthe spool, and a pointer extending from said rock shaft.

S. The combination substantially as` 'described, in an ammeter or voltmeter, of an electro-magnet secured upon a suitable base plate or support and having its magnetic axis vertical to said plate, and a visual indicator having a polarized magnetic bar or needle mounted within the field of said magnet and carrying at opposite ends suitable disks jor plates which show the direction ofthe current in the electro-magnet.

9. The combination in an ammeter or voltmeter, of an electro-magnet mounted upon a suitable base and having its magnetic axis vertical to said base, a rock shaft extending through the coil of the magnet and mounted IOO IIO

in brackets secured to opposite ends of thev spool for said magnet, a barror piece of iron hung from the rook shaft, a second bar or piece of iron fixed but of the same magnetic polarity, and a pointer projecting from said rock shaft and moving over a suitable scale, as and for the purpose described.

- Signed at New York, in the county of New York and State of New York, this 20th day of January, A. D. 1891.

Y WILLIAM HOCHHAUSEN. Witnesses:

WM. H. OAPEL, T. F. COUREY. 

